Lubricator with interchangeable ports

ABSTRACT

A lubricator is provided which has a unitized body with at least one port in communication with the body&#39;s bore and its outer surface, to which port(s) connectors with different outer fittings for further connection to other equipment may be attached and sealed, and later detached and replaced with other connectors. The connectors may have different outer fittings or may be a plug or valve. This allows the connection of a single port to external equipment to be changed and the fitting for that external equipment&#39;s connection to be altered, without having to disconnect the lubricator from its well-head and stem or any of the lubricator&#39;s other connections.

FIELD OF THE INVENTION

The invention relates to a plunger lubricator.

BACKGROUND

During fluid production operations, a plunger lift system is sometimes used when pressure within a wellbore is insufficient to cause fluid to rise naturally. In a plunger lift system, a plunger serves as a mechanical interface between lift gas below the plunger and produced fluid above the plunger. At the surface, a lubricator is used to absorb the kinetic energy of the plunger and to recover the plunger from the wellbore. The lubricator has fluid flow ports where produced fluids may exit.

Canadian patent no. 2,635,993 discloses a plunger lubricator housing, which comprises an elongated tubular body made from a single piece of material. The body has a first end, a second end, an outer surface, an inner surface that defines a plunger receiving interior bore, and radial ports which provide fluid communication between the interior bore and the outer surface.

BRIEF DESCRIPTION OF THE DRAWINGS

Drawings are included for the purpose of illustrating certain aspects of the invention. Such drawings and the description thereof are intended to facilitate understanding and should not be considered limiting of the invention. Drawings are included, in which:

FIG. 1A is a perspective view of a first side of a lubricator;

FIG. 1B is a perspective view of a second side of the lubricator; and

FIG. 2 is an exploded view of the lubricator.

DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS

The detailed description set forth below in connection with the appended drawings is intended as a description of various embodiments of the present invention and is not intended to represent the only embodiments contemplated by the inventor, The detailed description includes specific details for the purpose of providing a comprehensive understanding of the present invention.

However, it will be apparent to those skilled in the art that the present invention may be practiced without these specific details.

Referring to FIGS. 1A, 1B, and 2, a lubricator 20 comprises a body 1, the body having an outer surface 14 and an axial inner bore defined by an inner surface 16. The inner bore is for receiving a plunger (not shown). Lubricator 20 also includes a well head connection 15 at a first end for connecting to a well head (not shown), and a stem connection 17 at a second end for connecting to a stem (not shown). Lubricator 20 may be formed by forging, machining bar stock, casting, or a combination of known manufacturing methods.

Lubricator 20 further includes flow ports collectively designated 3 which allow fluid to flow between the inner bore and the outer surface 14. Flow ports 3 are each releaseably connectable to a first end of a flow line connector 5 having an inner bore for fluid to flow therethrough. Flow port 3 may be connected to the flow line connector 5 by various methods, Flow ports 3 may be recessed from outer surface 14 for receiving the first end of flow line connector 5. In one embodiment, outer surface 14 includes holes collectively designated 22 around flow ports 3 for receiving fasteners collectively designated 11. In a further embodiment, flow line connector 5 has flanges 24 and connector 5 may be secured to the body 1, with the connector's inner bore substantially aligned with the opening of flow port 3, by having its flanges 24 clamped on to body 1 by clamps collectively designated 4. Clamps 4 have apertures for receiving fasteners 11 and the length of fasteners 11 is sufficient to penetrate through clamps 4 into holes 22. When assembled, flange 24 is clamped between the body 1 and clamp 4, and clamp 4 is secured against body 1 by fasteners 11. Fasteners 11 may be screws and holes 22 may be internally threaded to mate with fasteners 11. In one embodiment, when connector 5 is connected to flow port 3, connector 5 extends radially outwardly from outer surface 14. A person skilled in the art can appreciate that there exist other ways to attach connector 5 to flow port 3, including a threaded connection wherein the first end of connector 5 is internally threaded and flow port 3 includes an externally threaded nipple for mating with the first end of connector 5, and vice-versa. An o-ring 10 may be included to fluidly seal the connection between flow port 3 and flow line connector 5. Other methods for sealing the connection, as known to those skilled in the art, may also be employed. A second end of the connector 5 is connectable to a flow line (not shown) by various methods, including a threaded connection. In one embodiment, the second end of connector 5 is internally or externally threaded for connecting to the flow line.

Lubricator 20 may also be provided with a port 18, which may be used for attaching gauges or sensors, or for injecting chemicals. Lubricator 10 may also comprise a catcher port 13 to catch a plunger at the top of its stroke. Ports 18 and 13 allow fluid to flow between the inner bore and the outer surface 14. Ports 18 and 13 are each releaseably connectable to a first end of a connector 7 and a catcher stemlet 2, respectively, Connector 7 and stemlet 2 may each have an inner bore for fluid to flow therethrough. Ports 18 and 13 may be connected to the connector and stemlet by various methods. Ports 18 and 13 may be recessed from outer surface 14 for receiving the first end of connector 7 and stemlet 2, respectively. In one embodiment, outer surface 14 includes holes around ports 18 and 13 for receiving fasteners collectively designated 12. In a further embodiment, connector 7 and stemlet 2 each have flanges and connector 7 and stemlet 2 may be secured to the body 1, with their inner bore substantially aligned with the opening of ports 18 and 13, respectively, by having their flanges clamped on to body 1 by clamps collectively designated 6. Clamps 6 have apertures for receiving fasteners 12 and the length of fasteners 12 is sufficient to penetrate through clamps 6 into the holes. When assembled, the flanges of connector 7 and stemlet 2 are clamped between the body 1 and clamps 6, and clamps 6 are secured against body 1 by fasteners 12. Fasteners 12 may be screws and the holes may be internally threaded to mate with fasteners 12. In one embodiment, when connector 7 and stemlet 2 are connected to ports 18 and 13, respectively, connector 7 and stemlet 2 extend radially outwardly from outer surface 14. A person skilled in the art can appreciate that there exist other ways to attach connector 7 and stemlet 2 to ports 18 and 13, respectively, including a threaded connection wherein the first end of connector 7 and stemlet 2 is internally threaded and ports 18 and 13 include an externally threaded nipple for mating with the first end of connector 7 and stemlet 2, and vice-versa. O-rings 8 and 9 may be included to fluidly seal the connections between port 18 and connect 7, and port 13 and stemlet 2, respectively. Other methods for sealing the connections, as known to those skilled in the art, may also be employed. A second end of the connector 7 or stemlet 2 may be connectable to another component, such as a gauge, a sensor, a chemical supply line, etc., by various methods, including a threaded connection. In one embodiment, the second end of connector 7 or stemlet 2 is internally or externally threaded for connecting to another component.

In one embodiment, lubricator 20 includes an equipment attachment which may be used for attaching a sensor to indicate the arrival of a plunger. In another embodiment, other components, such as lifting eyelets, are welded or otherwise attached to lubricator 20.

In one embodiment, body 1 is constructed from a single piece of material, which is machined, forged, or casted to form the inner bore and outer surface 14. The material of body 1 may be any metal meeting proper specifications for strength, temperature rating, ductility, durability, corrosion resistance, capability of being welded, worked or machined, typically a steel, and preferably 4130 or 4140 carbon steel. In a further embodiment, ports 3, 13, and 18 are machined into the body. Well head connection 15 is machined at the first end, and stem connection 17 is machined at the second end, Various connectors or stemlets may be connected to the ports using various methods, including those described above, In a further embodiment, outer surface 14 is machined to have an increased thickness at various points along the length of the lubricator 20 such that the lubricator 20 may have increased thickness about ports 3, 13, and 18, or at other locations.

Since connectors and stemlets are removably connected to the ports, the connectors and stemlets may be replaced individually when necessary without de-installing the whole lubricator from the wellhead. In addition, the lubricator described herein may have a standardized body that can be customized using a multiplicity of connectors and stemlets. This may reduce the inventory requirements of lubricators to supply all connector-type demands, and may also permit mixing and matching connections without additional machining or modification of the lubricator body.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to those embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein, but is to be accorded the full scope consistent with the claims, wherein reference to an element in the singular, such as by use of the article “a” or “an” is not intended to mean “one and only one” unless specifically so stated, but rather “one or more”. All structural and functional equivalents to the elements of the various embodiments described throughout the disclosure that are know or later come to be known to those of ordinary skill in the art are intended to be encompassed by the elements of the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. 

1. A lubricator for receiving a plunger comprising: a body having an outer surface, and an inner surface defining a bore, the body having at least one port allowing fluid to flow between the bore and the outer surface; a well head connection at a first end for connecting a well head; a stem connection at a second end for connecting a stem; and a connector having an inner bore, the connector being removably and sealably connectable to the at least one port.
 2. The lubricator of claim 1 where the connector's inner bore is in operable fluid communication through the port to which it is sealed and connected with the body's inner bore.
 3. The lubricator of claim 1 where the mechanism which provides removable sealable connection of the connector when operably connected to the lubricator comprises: a. Four bolt-holes with internal threads, each in the outer surface of the lubricator's body near to the port, b. an O-ring or seal means deployed between the inward end of the connector and the lubricator to cause a seal between those two parts when under compression, c. two grooves in opposite sides of the outer surface of the connector's circumference each for receiving compression block, d. two compression blocks with holes drilled therethrough each of which mates with a bolt-hole, and each block fitting into one of the grooves, the holes in perpendicular alignment with the bolt-holes, e. four bolts, one for each hole in the compression blocks, threaded to match the threads in the bolt-holes.
 4. The lubricator of claim 3 which when assembled has the bolts tightened in the threads of the bolt-holes to bias the compression blocks toward the lubricator body causing the connector to compress the seal, thereby being in sealed operable connection with the lubricator body with the connector's bore in fluid communication with the lubricator's bore.
 5. The lubricator of claim 1 where the connection between the connector and the lubricator body is by internal threads in the port mating with external threads on the inner end of the connector, coupled with sealing means.
 6. The lubricator of claim 1 where the outer end of the connector is supplied with a fitting for connection with other equipment.
 7. The lubricator of claim 5 where the fitting of the connector is one of: an internal thread, an external thread, a quick-release external profile, a clamp-ready surface for a compression fitting, or any other suitable or desirable connection-ready fitting for external equipment.
 8. The lubricator of claim 6 where the fitting of the connector is one of: an internal thread, an external thread, a quick-release external profile, a clamp-ready surface for a compression fitting, or any other suitable or desirable connection-ready fitting for external equipment.
 9. The lubricator of claim 4 where the operator may change the connector when external equipment requires different connectivity to the lubricator, without having to change the lubricator or alter any other connectors which may be included or used with the lubricator body.
 10. The lubricator of claim 5 where the operator may change the connector when external equipment requires different connectivity to the lubricator, without having to change the lubricator or alter any other connectors which may be included or used with the lubricator body.
 11. The lubricator of claim 4 where the connector is a plug.
 12. The lubricator of claim 5 where the connector is a plug.
 13. The lubricator of claim 1 with more than one connector.
 14. The lubricator of claim 4 with more than one connector.
 15. A method of changing a connection to a lubricator by changing a single removable and resealable connector for a similar connector with a different external fitting, without necessity of changing other connections to the lubricator or demounting the entire lubricator and replacing it with a differently configured lubricator. 